HP DL360 Reference And Troubleshooting Manual page 117

To examine the drive take-up leader, tilt the cartridge receiver door on
the front of the drive and look inside to see that the drive leader is
connected to the buckling link-hook, which should be engaged in the
leader slot.
DLT drive failure occurs
Action:
Be sure the power and signal cables are properly connected.
Be sure the power and signal cable connectors are not damaged.
If the drive is connected to a nonembedded controller, be sure the controller
is properly seated.
DLT drive does not read tape
Action:
Be sure the drive is seated.
Be sure the drive is installed properly.
Check each tape cartridge that has been used in the drive to see if a leader
was dropped. After you locate any bad cartridges, dispose of them. A
working tape drive will drop the leader of a bad cartridge, indicating that the
cartridge needs replacing.
Refer to the tape drive documentation to be sure the type of tape being used
is supported by the drive.
Server cannot find the DLT drive
Action:
Be sure a device conflict does not exist. Check for duplicate SCSI IDs in use
and refer to the documentation of the DLT drive and the array controller to
be sure they are compatible.
Be sure the maximum number of drives per controller has not been exceeded.
Refer to the controller documentation to determine the capacity of the
controller.
Troubleshooting 117